Float-operated snap-over switch



April 23, 1929. L. M. PERSONS FLOAT OPERATED SNAP OVER SWITCH Filed Hay 31, 1924 Patented Apr. 23, 1929.

UNITED STATES LAWRENCE M. PERSONS, OF CHICAGO, ILLINOIS. ASSIGNOR 'IO COOK ELECTRIC COM:-

IPANY, OF CHICAGO, ILLINOIS,

PATENT OFFICE.

A CORPORATION OFILLINOIS.

FLOAT-OPERATED SNAP-OVER SWITCH.

Application filed Ray 31,

My invention relates to electric switches and more particularly to an improved float operated snap-over switch.

An object of my invention is to produce a 6 float operated snap-over switch of exceeding simplicity which is certain and efllcient in operationv and devoid of delicate mechanism which is apt to require constant and frequent repair.

In carrying out my invention, I prefer to position the switch between the lower end of p the flbat and a parallel support extending beneath the surface of the liquid, so that the switch in effect serves as an interconnection between these parts at this point; This arrangement permits a definite minimum movement of the float, such as is necessary to operate the switch.

A further object of my invention is to arrange a spring of the snap-over switch so that the upward movement of the float is resisted until the resultant upward pressure of the liquid (or buoyancy) overcomes the spring. As the switch elements are biased. beyond dead center, the float assumes a' definite and positive movement upward, which is sufiicient to move the contact member with a snap action to off-position. The spring alsoresists the downward movement of the float as the level lowers, until the resultant upward pressure of the liquid is again overcome but by the weight of the float in this instance. In a similar manner the contact member will move to on-position and the circuit quickly closed cc tacle.

wish to point out the compact arrangement of the parts, their simplicity and the resulting economy, both in space and material. The receiving receptacle may be made smaller withoutlessening its capacity due to the decreased space occupied by .the device.

In order to apprise those skilled in the art how to construct and practice my inventlon, I shall now: describe an embodiment thereofin connection with the accompanying drawing-5'11.

' the drawings- Figure 1 is a side elevational view of a float operated electric switch disposed within a fluid container;

V Fig. 2 isfa perspective view of a support to eflect pumping of the liquid into the re 1924. serial No. 717,135.

adapted to extend beneath the surface of the Fig. 6 is a detail sectional view of the contact carried by the float support; and,

Fig. 7 is a sectional detail View of an insulated mounting of a float mechanism taken on line 77 of Fig. 1.

The float mechanism embodying my invention and associable with the snap-over switch, disclosed herein, comprises a support 2, the lower endof which extends beneath the surface of the liquid so that it will remain submerged. A float 3 is adapted to be connected at itsupper and lower ends to support 2. Support 2 preferably comprises a U-shaped member having its sides cut away to form openings 4. In the openings 4, the float -3 is adapted to move, which'movement is restricted by lateral extensions 5. Flanges-6 extend transverselyfrom the sides of support 2 and are apertured at 7 to receive'bolts 8. As illustrated in Fig. 1, the bolts 8 are adapted to project downwardly from a wall 9, which in this instance serves as a mounting for the float mechanism.

In the device disclosed, frame 2 may constitute one side of the circuit. The bolt 8 is, therefore, insulated from the support 2 by the provision of an insulated collar 10 seating in the apertures 7, and by a pair of insulation washers 11 separating the support 2 from the wall 9 and the nut12 at the end of bolt 8. 1

Support 2 is preferably of a metal stamping so that it will be light and inexpensive to manufacture. To permit an eflicient circulation of fluid about support 2 so that any vari ation in the liquid levelwill immediately effect the float 3, the back wall-13 of support 2 is aperturedat 14.. This also tends to increase theilightness of the float mechanism.

-shaped brackets are atare apertured at 16, which, together with the apertured ears 15, receive an interconnecting yoke member 16. As will be noted in Fig. 3, yoke member 16 is provided with the legs 17, the outer ends'of which engage in the apertures 16. The yoke member 16 is also pro- 7 vided with the lateral ears 18, which are the switch will always'remain submerged adapted for reception in the apertured ears 15.

At the lower end, a snap-over switch 25 is disposed between the support 2 and the float 3. The switch elements comprise a pair of yoke members 26 and 27, pivoted at adjacent points in the lower lateralextensions 5. Yoke member 26 serves as the contact member of the switch, but yoke member 27 comprises the interconnecting means between support 2 and the lower end of float 3. As will be noted in Fig. 4, a coil spring 28 spans the yoke members 26 and 27, the ends of which spring en gage in notches 29 for retaining this spring centrally between the yoke members 26 and 27. The spring 28 tends to draw together the opposite ends of the yoke members when they are biased in either direction from their dead center relation. When biased in an upward direction, the spring 28 acts to draw the contact 26 upwardly against a stop 30, as illustrated in Fig. 5. Stop30 in the present case comprises the portion of the lower edge of the back 13 turned inwardly adistance sufiicient to intercept the contact 2 before reaching the limits of its upward movement.

When the yoke members 26 and 27 are biased in a downward direction from their dead center relation, the contact yoke member 26 engages a terminal 31 towhich the leadwire 32 is connected, this being clearly shown in Fig. 2. I have illustrated in detail in Fig. 6, however, a sectional view of terminal 31. A bolt 33 passes through an insulated aperture 3 L in the back wall 13 of support 2, while fiber washers 35 serve to space the leadwire 33 and a terminal lug 36 away from this wall 13. p

Lug 36 is also positioned to; intercept contact member 26 before reaching its lower limit of movement. It will be ngted that b disposing the snap over switch between t e submerged lower end of support 2 and thelower end of float 3,

The particular arrangement of the .parts 26 and 27 and the spring 28 prevents float 3 from assumin a gradual movement with the rise and fall of the liquid level in the receptacle. However, the float' is under controlof the liquid level. With the float in its lower position, as illustrated in Fig. 1, the contact member 26 is in en agement with the terminal lug-36 to close the circuit: The pump for pumping the liquid into the receptacle then operates until a predetermined level, say line A-B indicated in Fig. 1, is reached. This level is such that. the resultant "upward pressure of the liquid a ainst the submerged portion of float 3 is suflicient to overcome spring relation, and in so doing overcomes the resistance of the spring. l'Vhen moving beyond this dead center relation, the spring rapidly draws contact member 26 out of engagement with the terminal lug 36.- Thus the contact is quickly broken. It will be noted that the spring will accelerate the movement of float 3 when moving beyond dead center.

The same action takes place in the downward travel of the float. When the resultant upward pressure of the fluid is no longer sufiicient to sustain the weight of float 3, say the level indicated at CD in Fig. 1, the float will drop by gravity, bringing the yoke member 27 beyond its dead center relation with the contact member 26. Thus, the spring will bring the contact member into snap engagement with the terminal lug 36 to close the circuit. One side of the circuit denoted by the lead-wire 38 is grounded to the frame at 39.

From the foregoing description it will be apparent that I have provided-an improved float operated switch which is associable with a float mechanism having a float provided with a definite minimum movement to operate the switch. If desired, my device may be employed in receptacles of any size. It will be noted that the support 2 is in parallel relation with the float 3 and that the float 3 moves substantially in a perpendicular plane. Lateral extensions 5 serve as stops to limit the movement of float 3 as soon as contact member 26 is thrown past dead center relation in either direction. This restricts the float to a' minimum movement which requires less space for its operation.

' Without further elaboration, the

that others may, by applying current knowlforegoing will so fully explain the gist of my invention,

edge, readily adapt the same for 'use under varying conditions of service, without eliminating' certain features whichmay properly be said to constitute the essential items of novelty involved, which items are intended to be defined and secured to me by the following claims.

in either direction from a dead center relation, a contact upon said support submer in the liquid and in the path of one of said 3 yokes, and a float for tilting the other of said yokes for effecting a quick make and break of the circuit at said contact.

2. A float operated snap-over switch for use in a liquid container comprising a support provided with side openings in which a float is adapted to move and to have limited perpendicular movement, a connection at each end of the float for loosely securing the same to the support, and contact members one of which is interconnected to one of said connections so as to efl'ect movement of the contact member upon movement of the float.

3. A float operated snap-over switch for use in a liquid container comprising a support and a float connected thereto at each end, contact members one of which is pivoted to said support at its lower end, and means for operating said pivoted contact member through the lower float connection upon movement of the float.

4. A float operated snap-over switch having circuit making and breaking elements for use in a liquid container comprising a support provided with spaced lateral extensions arranged in pairs at the upper and the lower ends, a float movable between the upper pair and the lower pair, a yoke member bridged across said upper pair and pivotally connecting the float to the support, a second yoke member bridged across the lower pair and pivotally connecting the float to the lower end of the support, and a third yoke member constituting one of the circuit making and breaking elements of the switch interconnected with said second yoke member for operation upon movement of the float.

5. A float mechanisrfl embodying an electric switch adapted to be operated thereby, and capable of detachment from its mounting as an assembled unit comprising a float, a framemember arranged to limit the movement of the float between the ends of the frame member, and loose pivotal connections between said ends of the frame member and the ends of the float.

6. A float mechanism for operating an electric switch adapted to be detachable as a unit from its mounting comprising a frame member provided with a side opening in which the float is adapted to move, and an electric switch serving as the interconnecting means lfiletwecn one end of the frame member and the oat.

7. In combination, a float, a parallel support extending beneath the surface of the liquid, and a snap-over switch arranged between said float and said support at the lower end for operation upon movement of the float.

8. In combination, a float, a parallel support extending beneath the surface of the liquid and connected to said float at each end, and a snap-over switch arranged at the lower end of said float for operation upon movement of the float.

9. In combination, a float, a parallel support extending beneath the surface of the liquid, means for connecting the ends of the float with said support, and lateral projections on the ends of said support for serving as stops to restrict the movement of said float.

10. A float controlled switch comprising a support, a pair of oppositely arranged members connecting one end of the float to said support, said support providing pivotal mountings for said members at their adjacent ends whereby the other ends are movable, one to contact with a terminal of the circuit and the other pivotally to connect to the float, and an over-center spring for initiating and thereafter accelerating the opening and closing movements of said terminal contacting member imparted thereto by said float.

In witness whereof, I have hereunto sub-.

scribed my name.

LAWRENCE M. PERSONS. 

